As a new generation optical network which completes automatic switching function under control of route selection and signaling, Automatic Switched Optical Network (ASON) is a study hotspot of the optical network field in recent years. The introduction of ASON technology can enhance the quick configuration capability of network traffics, improve the survivability of traffics, effectively resist against network multi-point fault, and flexibly provide different traffic levels to meet the demands of rapidly developing customized traffics at present.
The Path Computation Element (PCE) in ASON enables the path computation function to be independent from network equipment, that is, an independent PCE is arranged in a network to solve the problem of special resources required by a large amount of lines in a Multiple Protocol Label Switching/Generalized Multi-protocol Label Switching (MPLS/GMPLS) due to constrained path computation. As the PCE has to compute the route computation and path resource selection requested by each fault traffic which needs the recovery of rerouting one by one, particularly in a case that a large amount of traffics request the fault recovery route computation simultaneously, delay of traffic recovery may be caused as the PCE is too busy to respond requests in time.